It is generally known that camshaft adjusters permit optimum valve timings over a broad range of loads and rotational speeds. Significant reductions in emissions and fuel consumption are thus implemented. In addition, driving enjoyment is significantly increased by optimizing the torque and power. According to the prior art, a distinction is made between electrical camshaft adjusters and the hydraulic camshaft adjusters mentioned at the outset.
In the area of hydraulic camshaft adjusters, rotors are known which include a first rotor element and a second rotor element. This is disclosed, for example, in the German unexamined patent application DE 10 2009 053 600 A1. In this case, the two rotor elements are connected or sintered with the aid of pins. Another specific embodiment for connecting two rotor elements of a rotor is described in the German unexamined patent application DE 10 2008 028 640 A1. Two rotor elements are provided here in such a way that they may be joined together on the basis of their particular “own” geometry. In addition, the European patent specification EP 2 300 693 B1 describes two identical, joined rotor elements, which have a form fit and a press fit to form the oil channels. A design of the rotor as an assembly system is disclosed in the European patent specification EP 1 731 722 B1, the rotor core and the cover forming the oil channels. In the aforementioned publications, the oil penetrating between the two rotor elements generates internal and external leaks between two oil channels in each case. These leaks cause a pressure drop in the assembled rotor and thus a reduction in the adjusting speed of the hydraulic camshaft adjuster.
Another hydraulic camshaft adjuster, which includes a first and a second rotor element, is disclosed in the German unexamined patent application DE 10 2011 117 856 A1. The two rotor elements here seal oil channels with the aid of sintered bevels. The problem with this approach, however, is that a rebound of the two rotor elements occurs in the longitudinal interference fit during the operation of the camshaft adjuster.